VI CONTENTS. 



PLATYHELMINTHES (Continued). PAGE. 



NEMERTINEA 44 



Tetrastemma 44 



NEMATHELMINTHES 46 



Asearis 46 



Trichina 47 



TROCHELMINTHES 48 



ROTIFERA 48 



Brachionus (A Rotifer) 48 



MOLLUSCOIDA 50 



POLYZOA 50 



Bugula 50 



Plumatella 52 



BRACHIOPODA , 52 



Terebratulina 52 



ECHINODERMATA 54 



ASTEROIDEA 55 



Asterias (Starfish) 55 



OPHIUROIDEA 60 



Ophiura (Serpent-Star) 60 



ECHINOIDEA 61 



Arbacia (Sea-Urchin) 61 



HOLOTHUROIDEA 67 



Thyone (Sea-Cucumber) 67 



ANNELIDA 70 



CH.ETOPODA 71 



Nereis virens (Clam-Worm) 71 



Lumbricus (Earthworm) 74 



Autolytus cornutus 80 



Lepidonotus squamatus 81 



Diopatra cuprea 81 



Chaetopterus 



Amphitrite ornata 83 



Cistenides gouldii 84 



Clymenolla toi-quata . . 84 



Arenicola cristata 85 



Sabolla microthalma 85 



Hydroides 86 



Spirorbis borealis 86 



GEPHYREA S(> 



Phasc'olosoma 86 



MOLLUSCA 89 



LAMELLJBRANCHIATA 91 



Venus nicm-naria (Quohog) 91 



Yoldia limatula 99 



Mytihis or Modiola (Mussels) ... 100 



IVrton irradians (Scallop) 101 



Ostrea virginiana (Oyster) 103 



Solenomya lO.'i 



Mya arenaria (Long Clam) lot 



Ensis directus (Razor-shell Clam) 105 



